The transmission efficiency of WPDX135-40-3KW worm gear reducer (usually in the range of 65%~80%) is affected by a combination of various factors. The core is based on the characteristics of worm gear and worm transmission 'sliding friction-dominated, and multi-component collaborative work' and can be mainly classified into four categories: meshing sub-core characteristics, lubrication system status, structural design and manufacturing accuracy, and operating conditions . The specific analysis is as follows:
1. Characteristics of worm gear and worm meshing pairs (the most critical influencing factor, accounting for more than 60%)
The worm gear and worm transmission is mainly 'sliding friction as the main and rolling friction as the auxiliary'. The design, material and coordination accuracy of the meshing pair directly determine the basic transmission efficiency.
1. Number of worm heads and transmission ratio
Worm head count : is the core variable that affects efficiency. The more worm heads (number of threads), the larger the lead angle, and the lower the proportion of 'sliding friction components' during meshing, the higher the efficiency.
This model has a transmission ratio of 40 (large transmission ratio), usually paired with a single-head worm (single-head worm has a small lead angle, which can achieve a large transmission ratio), with a high sliding friction ratio, and a lower efficiency than a double-head/three-head worm (single-head efficiency is about 10%~15% lower than double-head).
Indirect influence of transmission ratio : the larger the transmission ratio, the more teeth and the larger the diameter of the worm gear, the longer the meshing contact path between the worm and the worm gear, the more sliding friction loss accumulates, and the efficiency decreases as the transmission ratio increases.
2. Worm gear and surface quality
Material matching :
The worm must have high hardness to resist wear (such as 20CrMnTi carburizing and quenching, hardness of 58~62HRC);
The worm gear needs to have high friction reduction to reduce the friction coefficient (such as tin bronze ZCuSn10Pb1, aluminum bronze ZCuAl10Fe3).
If the worm gear uses ordinary cast iron (poor friction reduction), the friction coefficient will increase from 0.05~0.07 to 0.1~0.12, and the efficiency can be reduced by more than 15%.
Surface finish : The roughness of the tooth surface directly affects the micro friction resistance. If the roughness of the worm spiral surface is optimized from Ra1.6μm to Ra0.8μm and the tooth surface of the worm gear is optimized from Ra3.2μm to Ra1.6μm, the friction resistance of the tooth surface can be reduced by 20% to 30%, and the meshing efficiency is significantly improved.
3. Meshing accuracy and assembly clearance
Processing accuracy : If the worm tooth shape error (such as tooth pitch deviation, spiral line error) exceeds the 7th level of accuracy of GB/T 10089, or the worm gear ring radially jumps too much, it will lead to 'point contact' rather than designed 'surface contact' during meshing, local pressure is concentrated, friction is intensified, and efficiency is reduced by 5% to 10%.
Assembly clearance : The engagement clearance must be controlled at 0.2~0.4mm. Too small gap will cause 'stuttering friction', and too large gap will cause meshing impact and empty-span loss, both of which will reduce efficiency. In addition, if between the worm and the worm gear the deviation of the center distance exceeds the standard, it will lead to biased load friction and further reduce efficiency.
